Electric lamp



Sept.14, 1948. w. J. ALLPl-IIN ELECTRIC LAMP 3 Shets-Sheet 2 Filed May 29, 1947 nml f J. gymphl'm lJi 14, 1.943- wfJ. ALLPHIN 42,449,268

ELECTRIC LAMP i 'Filed May 2,9. 1947 3 Sheets-Sheet |40- Y B00 r |40 loo' l '00;

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. wam) .ATTORNEY dlepower distribution is plotted.

Patented Sept. 14, i948 UNITED'STATES PATENrFnca-- 2,449,268 l 1 ELCTRICLAMP y p wilma J. Aupnin. Danvers. Mese.. enigmi-to Sylvania Electric Products Inc.,` i a corporation `of Massachusetts Salem, Mass.,

Application May es, 1947, serial No.. 151.171.V i claim. .(ci. 11s-s4) This invention relates to electric lamps and more particularly to electric lamps which are especially adaptable for use in oor and table lamp xtures.

An object of thisinvention is to provide an electric lamp whichwill furnish both direct and indirect light.

Another object is to provide an electric lamp which furnishes both an upward ux for indirect illumination and a diffused downward :flux to give ample work-plane illumination.l

Further objects, advantages, and features will be apparent from the following description when read in conjunction with the accompanying drawing in which:

Figure 1 is a side elevational view of a lamp of my invention with the bulb thereof partially cutaway to show the location and construction of the filament.

Figure 2 is a top perspective View of the lamp of my invention.

Figure 3 is a schematic diagram illustrating certain shade design features which give a very satisfactory light-distribution pattern.

Figures 4, 5 and 6 are side elevational views of lighting fixtures illustrating different types of shade supports which may be` employed with the lamp of my invention.

Figure '7 is a graph on which the average can- The lamp, as shown in Figure 1 comprises a wardly to provide indirect lighting. The top portion li of the bulb is frosted in the conventional manner.

A glass mount 5 is sealed in the end of the bulb neck. The mount is provided with an aperture E therein and a glass tube 1 through which the bulb may be evacuated. A filament il is supported withinl the bulb by a pair of lead wires 9 and I0 and a leg Il. The fila-ment 8 comprises an elongated wire with two coiled coil portions i2. One end of the leg Il is connected to the filament wire -between the two coiled coil portions and serves as a support for lthe lament. The lower portion of the neck 2 is capped by a metal base i3. The outer end of the lead-wire 9 is connected to the side wall of the base I3 and the outer end-of the lead wire I0 is connected to a metallic button it on the bottom of the base it.

The lamp of my invention is designed primarily for use in floor and table lighting xtures in which the lamp is installed base down, as shown in Figure 3. In this ligure the lamp is mounted base down in a receptacle i5 which isl mounted on top of a standard i6. A wide variety of shades may be satisfactorily used with the subject lamp. Three different shades designated by the numerals l1. 'i8 and I5 are shown bulb i in which the neck portion 2 'is provided with an inside translucent white coating 3 which extends from the lower portion of the neck to a point on the tops a short distance beyond the maximum diameter of the bulb. For example, in the instant illustration, the maximum bulb diameter is about 5% inches and the coating 3 extends along the top surface 4 for a, distance of about 3A inch measured radially thereacross. I have found that if the coating 3 extends across the top surface of the bulb substantially more than 1% inch a considerable amount of light is trapped in the bulb. If, on the other hand, the

coating 3 extends across the top substantially less than 3A Linch or if it only extends to the maximum diameter of the bulb, either the shade, which is normally employed with the lamp, is characterized by a very bright area near the top thereof, and a relatively dim area at the center and lower portion, or the bulb has to be posi.

tioned so high in the xture, with reference to the shade, that there is considerable glare when the fixture is viewed from the top. The translucent white coating 3 diffuses the direct light schematically in Figure 3. Almost any shade which nts within the lines formed by the 40 cone on top and the 70 c'one at the bottom will Vgive very satisfactory results. The apex of the upper cone is at the filament and of the lower c cone is about 11/2 inches below the ila-ment.

Figures 4. 5, and 6 show three different types of adapters which may be employed to support a shade. In Figure 4, the adapter 20 is of the hemispherical type and comprises three arcuate legs 2l connected'at their lower ends to a ring which may be seated in and secured to :a collar 22 onthe receptacle l5. A ring 23, on which the shade 24 is supported, is mounted on Vand supported by the upper ends of the legs 2|.

In Figure 5, the adapter 3l is of the harp type, the lower portion thereof being provided. with a. suitable collar through which the adapter is connected to the standard 25. The top of the adapter may be providedwith a threaded member or a screw to provide for securing the shade 26 thereto. The screw or threaded member may be capped by a nial 21. Y

In Figure 6, the adapter 28 comprises a plurality of resilient legs 29 which clamp on the lamp l and provide a support for the shade30.

Figure 'ly shows the average candlepower distrlbution from a lamp of the type just described which is. rated at 2M Watts and 120 Volti.

'What I claim is:

'n combination, an incandescent lamp combiisin'g a bulbous envelope, a. filament mounted in said envelope. a translucent coating on the iXi/nei` wail o! said envelope extending over the neck portion and slightly beyond the maximum diameter thereof. and a shade enciosihi said lamp, said shade being open at the top and. the bottom thereof and delinin in conjunction with said lamp a cone of light of about 40 degrees at .the top thereof and about 70 degrees at the bottom thereof. the apex of said ilist mentioned cone beine tsaid lament and the apex of said secas l0 Number y REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date 467,576 Cvuttman` Jan. 26. 1892 FOREIGN PATENTS Number Country Date 155,263 Switzerland Aug. 16, 1932 

